Document feed mechanism

ABSTRACT

The invention pertains to a document feeding mechanism for selectively lowering a document deck to engage a feed roll to effect sequential feeding of documents from the hopper. The document supporting bed is controlled by a cam driven articulated pivot latch which is magnetically actuated to cause the articulated portions to be locked to one another for pivoting as a unitary structure.

United States Patent Inventor Boyd M. Brue Rochester, Minn. Appl. No.770,505 Filed Oct. 25. 1968 Patented Feb. 9, 1971 Assignee InternationalBusiness Machines Corporation Armonk, N.Y. a corporation of New YorkDOCUMENT FEED MECHANISM 3 Claims, 3 Drawing Figs.

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Field of Search [56] References Cited UNITED STATES PATENTS 3,383,1065/1968 Brown 271/44 3,279,790 10/1966 Steinke et al. 271/41 PrimaryExaminer-Ev0n C. Blunk Assistant Examiner-Joseph WegbreitAttorney-Hanifin and Jancin and Robert W. Lahtinen ABSTRACT: Theinvention pertains to a document feeding mechanism for selectivelylowering a document deck to engage a feed roll to effect sequentialfeeding of documents from the hopper. The document supporting bed iscontrolled by a cam driven articulated pivot latch which is magneticallyactuated to cause the articulated portions to be locked to one anotherfor pivoting as a unitary structure.

PATEN'TEU FEB 919m m), gm

ATTORNEY 1 DOCUMENT FEED MECHANISM BACKGROUND OF TH E INVENTION Whenprocessing unit record documents such as cards through high speedprocessing machinery the documents must be rapidly and timely suppliedby a feeding mechanism in a predetermined manner, usually singly insequence and without damage. This is accomplished either by feed knivesor friction rolls or belts. With elevated speeds and the consequent highinitial acceleration the use of feed knives is likely to damage thedocuments. The alternative feed rolls or belts must be selectivelybrought into engagement with the document stack and overcome thefriction between adjoining documents to shear the endmost document fromthe remainder of the stack. The control of the feed must be positive ineffecting sufficient frictional engagement causing neither irregular orinterrupted document feeding. The control must be positive and notsubject to erratic functioning which would permit uncontrolled actuationresulting in document jams or erroneous operation.

SUMMARY OF THE INVENTION In the document feeding device of the presentinvention, a continuous running feed roll drives one card at a time fromthe stack supported in the hopper. The feed roll is permitted to engagethe document to be delivered by magnetic actuation which locks togetherarticulated portions of a latch structure for unitary pivotal movement.One portion of the latch structure is fixed to the pivotable documentsupporting bed plate and the other portion has a cam follower surface.Accordingly when the latch structure pivots as a unit a document isengaged and fed into the device by the exposed feed roll. An emitterdisc is secured to a common shaft with the cam and has associatedtherewith emitter pickups which initiate and terminate energization ofthe electromagnet in response to feed commands. Since the cam rotates ata speed which is a multiple of the feed rate of the associated device itis unnecessary to lose a full cycle if a delay occurs in the feedcommand since the latter can be executed during the next subsequentrevolution of the cam.

It is an object of the invention to provide an improved document feedingapparatus which is positive in control action while simplified instructure. It is a further object of this invention to provide adocument feed control actuable without the loss of a full cycle should adelay in the feed command occur.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric view partlybroken away of a portion of a parallel feed hopper including a pivotlatch mechanism. FIG. 2 is a side elevation partly in section of ahopper utilizing the mechanism of FIG. 1. FIG. 3 is a side elevation ofthe latch mechanism of FIG. 1.

DETAILED DESCRIPTION As seen in FIG. 1 a bed plate shaft assemblyincludes a shaft 11 to which is secured a front bed plate 12, a latchframe 14 and a latch arm spring 16 to form a unitary structure. Thelatch frame 14 has secured rigidly thereto a pivot pin and anelectromagnet core 18 with depending legs or core elements 19, one ofwhich is surrounded by coil 63. Joumaled about pivot pin 20 is anoscillating latch arm 22 in the form of a bellcrank wherein oneprojection arm 23 serves as an armature confronting the electromagnetpoles or core elements 19 and the other leg 24 presents a cam followersurface. A bed plate spring bracket 26 is secured along the web portion27 thereof to the machine frame. Bracket 26 presents a flange 28 towhich one end of main spring 30 is secured and a flange 31 which servesas an abutment against which the downwardly depending projection 33 oflatch frame 14 is retained. An aperture in a depending projection 33receives the opposite end of spring 30 with the biasing force of thespring exerted to normally retain projection 33 against the flange 31.The latch arm spring 16 is positively secured at one end to bed platepivot shaft 11 with the opposite free end abutting the upper projection35 of the pivot latch 22 to bias the pivot latch leg 24 into engagementwith eccentric cam 39. The eccentric cam 39is secured to the cam shaft40, rotated by a drive means not shown and has positively fixed theretoat its opposite end an emitter disc 42. The cam shaft assembly rotatesin the direction of arrow A causing the emitter or emitter disc 42 tomove past the emitter pick ups 44 and 45.

As seen in the schematic vertical section of FIG. 2. a card deck 47 issupported within the hopper, inclined against a rear sidewall 50 andfurther confined between a pair of end walls 51, one of which is shown.A series of continuously running feed rolls 53 secured to a common shaft54 are interdigitatcd between the support tabs 55 to permit the supporttabs to hold the card deck immediately above and out of engagement withfeed rolls 53. The card deck 47 receives further support on the rear bedplate 56 while the hopper is provided with a threat knife 58 to insuredelivery of one document at a time from the hopper to document guidewayof the associated machine. Documents or cards initially moved throughthe throat beneath throat knife 58 by the driving force of thefrictionally engaged feed rolls 53 thereafter are confined between thethroat roll 60 and nudge roll 61 which assume control of the card anddrive the card at the transport speed of the machine.

In operation the main tension spring 30, holding frame projection 33against the stop of bracket flange 31 maintains the bed plate shaft 11and front bed plate 12 in a rotational position whereat the support tabs55 maintain the card deck 47 within the hopper in an elevated disengagedposition with respect to feed rolls 53. Continuously driven cam shaft 40causes cam 39 to drive the oscillating latch arm 22 against the biasingforce of leaf spring 16 and pivot the annature 23 downward once duringeach rotation of the cam. During the fall of cam 39 latch arm 22 pivotsallowing armature 23 to approach the pole faces of core elements 19, butat the low point of the cam a slight clearance is maintained between thearmature and pole faces to prevent impact during each rotation of cam 39which occurs while coils 63 are deenergized. The emitter pickup 44,which causes the magnet coil 63 to be energized, is positioned in aselected angular position prior to the low point of the cam profile topermit the magnetic force to build to the required value at the lowpoint of cam 39. When a feed command is issued the next passage of theemitter past the emitter pickup 44 causes the electromagnet coil 63 tobe energized and attract the armature 23 to the magnet pole faces of thecore legs 19 thereby securing oscillating latch arm 22 to latch frame 14as a unitary rigid portion of the bed plate shaft assembly. Oscillatinglatch arm 22, latch frame 14 and rear bed plate 12 now pivot as a unitcausing the support tabs 55 to pivot downwardly exposing the upperdriving surface of the feed rolls 53 to contact the lowermost cardpresent in deck 47 and drive it beneath throat knife 58 to effectdelivery from the hopper. When cam shaft 40 has rotated to the positionto bring the emitter to a position confronting emitter pick 45. a signalis issued deenergizing the electromagnet coil 63 and freeing oscillatinglatch arm 22 for movement independent of the bed plate shaft assembly,whereupon the main tension spring 30 restores the latch frame projection33 to abutting relation with bracket flange 31 and rear bed plate 12 ispositioned with bed plate tabs 55 positioned to support card deck 47above and out of engagement with the feed rolls 53. The signal fromemitter pickup 45 occurs at a position of angular displacement prior tothe bottom center position of cam 39 to allow the magnetic field todecay sufficiently to effect release of the armature at such bottomcenter position of the cam, thereby minimizing the impact forces as theframe projection 33 restores to a position of abutment with flange 31.

During each feed cycle the upwardly extending projection 65 of rear bedplate 12 pivots toward card deck 47 to provide a joggling action of thecards. This provides a card joggling capability that functions duringeach feed cycle.

The cam shaft 42 rotates at a rate that is some multiple of the desireddocument feed rate. As the consequence if there is a delay in thecommand for the next feed cycle, a feed com mand when issued will beexecuted on the next subsequent rotation of the cam shaft andaccordingly only a fraction of a feed cycle is lost as a result of suchdelay. By way of example,

if the cam rotates at a speed four times the normal feed rate of 5 thehopper mechanism, a delayed feed command will cause a card to be fedduring the next succeeding rotation of the cam which occurs during eachquarter of the normal feed cycle. As a result only a quarter cycle islost rather than a full cycle where a slight delay occurs in the feedcommand. Thus, depending upon the multiple of the feed rate at which thecam shaft operates, the delay occasioned by a late command from theassociated processor is only one third, one fourth, one fifth, etc. of anormal document feed cycle.

lclaim:

1. Apparatus for feeding documents from a stack comprising:

a hopper;

a continuously driven feed member;

a pivotable means including a document supporting bed member selectivelypivotable between a first position whereat a document stack supported onsaid bed member is retained above and out of engagement with said feedmember and a second position permitting the lowermost document of saidstack to engage said feed member whereby such document is sheared fromsaid stack and delivered from said hopper;

a first element secured to said pivotable means for movement in unisontherewith;

a second element pivotally secured to said first element;

drive means engaging and periodically pivoting said second element; and

electromagnet means mounted on said first element and selectivelyactuable to retain said elements fixed with respect to one another tocause said drive means to pivot said first and second elements inunison.

2. The apparatus of claim I wherein said second element comprises a bellcrank pivotally connected to said first element with one arm that formsan armature adjacent the pole of said electromagnet and the other armpresents a cam follower surface and said drive means which engages saidsecond element comprises a cam, whereby said second element is pivotedby each rotation of said cam and said first member. bed member and bellcrank are pivoted as a unitary structure by said cam when saidelectromagnet is actuated.

3. The apparatus of claim 2 further comprising first biasing meansurging said document supporting bed member toward said first positionand second biasing means urging said bell crank and other arm towardengagement with said cam.

1. Apparatus for feeding documents from a stack comprising: a hopper; acontinuously driven feed member; a pivotable means including a documentsupporting bed member selectively pivotable between a first positionwhereat a document stack supported on said bed member is retained aboveand out of engagement with said feed member and a second positionpermitting the lowermost document of said stack to engage said feedmember whereby such document is sheared from said stack and deliveredfrom said hopper; a first element secured to said pivotable means formovement in unison therewith; a second element pivotally secured to saidfirst element; drive means engaging and periodically pivoting saidsecond element; and electromagnet means mounted on said first elementand selectively actuable to retain said elements fixed with respect toone another to cause said drive means to pivot said first and secondelements in unison.
 2. The apparatus of claim 1 wherein said secondelement comprises a bell crank pivotally connected to said first elementwith one arm that forms an armature adjacent the pole of saidelectromagnet and the other arm presents a cam follower surface and saiddrive means which engages said second element comprises a cam, wherebysaid second element is pivoted by each rotation of said cam and saidfirst member, bed member and bell crank are pivoted as a unitarystructure by said cam when said electromagnet is actuated.
 3. Theapparatus of claim 2 further comprising first biasing means urging saiddocument supporting bed member toward said first position and secondbiasing means urging said bell crank and other arm toward engagementwith said cam.